1. Field of the Invention
The present invention relates to an object, a method, or a manufacturing method. Further, the present invention relates to a process, a machine, manufacture, or a composition of matter. In particular, the present invention relates to, for example, a semiconductor device, a display device, a light-emitting device, a driving method thereof, or a manufacturing method thereof. In particular, the present invention relates to, for example, a liquid crystal display device and an electronic device using the liquid crystal display device.
2. Description of the Related Art
Liquid crystal display devices for mobile use such as smartphones and tablets are in their heyday. It is reported that despite slow down in sales of home-use televisions and the like, some liquid crystal devices have been sold well such that demand outstrips supply. There is always replacement demand for mobile devices usually replaced in a few years, which is different from the case of home-use televisions, and thus the mobile devices are lifelines of Japanese display industry in a slump.
Development of highly refined goods is essential to create the replacement demand; accordingly, displays with high image quality and reduced frame width have been demanded.
A liquid crystal display device has a structure in which a liquid crystal material is sealed in a space between a pair of substrates whose periphery is firmly attached with a sealant. In general, one of the pair of substrates is provided with a color filter and a black matrix, and the other thereof is provided with a driving element in the case of an active matrix liquid crystal display device.
In order to prevent moisture absorption and water penetration due to exposure of a planarization film on an element substrate side to the outside atmosphere, Patent Document 1 discloses a structure in which a planarization film is provided so that an end portion thereof overlaps with a sealant.
There has been growing demand to reduce a non-display area positioned outside an effective display area, i.e., the width of a frame area, in a liquid crystal display device. A large-size display with a frame width of several millimeters and even a small-size display with a frame width of less than 1 mm have been released.
Although being used for sealing or needed for mounting of a driver, the frame area is greatly reduced due to a reduction in the width.
A sealant used for sealing is a resin and thus has low moisture permeability but does not completely shield against water. Conventionally, a certain width can be used for a sealing region; thus, influence of water from the outside atmosphere can be reduced at least for a period in which a device is driven.
In these days, since a reduction in a frame width is underway, it is difficult to secure a sufficient frame width.